U.S. patent application number 11/254659 was filed with the patent office on 2006-04-27 for multi-chip image sensor module.
This patent application is currently assigned to ChipMOS TECHNOLOGIES (Bermuda) LTD.. Invention is credited to Yeong-Ching Chao, Yao-Jung Lee, An-Hong Liu.
Application Number | 20060087018 11/254659 |
Document ID | / |
Family ID | 36205459 |
Filed Date | 2006-04-27 |
United States Patent
Application |
20060087018 |
Kind Code |
A1 |
Chao; Yeong-Ching ; et
al. |
April 27, 2006 |
Multi-chip image sensor module
Abstract
A multi-chip image sensor module includes a flexible module
board, an image sensor chip, a transparent cover, and at least an
IC chip. The flexible module board has a first die-attached
portion, a second die-attached portion, at least one bent portion,
and at least one bonding portion where the bent portion connects
the first die-attached portion and the bonding portion. The image
sensor chip is attached to the first die-attached portion and the
IC chip is disposed on the second die-attached portion. Inner leads
on the bonding portion are electrically connected to the bonding
pads of the image sensor chip when the bonding portion is bonded on
the image sensor chip. The transparent cover is disposed above the
sensing area of the image sensor chip, preferably adhered to the
bonding portion.
Inventors: |
Chao; Yeong-Ching; (Tainan,
TW) ; Liu; An-Hong; (Tainan, TW) ; Lee;
Yao-Jung; (Tainan, TW) |
Correspondence
Address: |
TROXELL LAW OFFICE PLLC
SUITE 1404
5205 LEESBURG PIKE
FALLS CHURCH
VA
22041
US
|
Assignee: |
ChipMOS TECHNOLOGIES (Bermuda)
LTD.
ChipMOS TECHNOLOGIES INC.
|
Family ID: |
36205459 |
Appl. No.: |
11/254659 |
Filed: |
October 21, 2005 |
Current U.S.
Class: |
257/680 ;
257/E25.032 |
Current CPC
Class: |
H01L 2224/73204
20130101; H01L 25/167 20130101; H01L 27/14618 20130101; H01L
2924/19105 20130101 |
Class at
Publication: |
257/680 |
International
Class: |
H01L 23/02 20060101
H01L023/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 21, 2004 |
TW |
093216782 |
Claims
1. A multi-chip image sensor module comprising: a flexible module
board having a first die-attached portion, a second die-attached
portion, at least one bent portion, and at least one bonding
portion, wherein the bent portion connects the first die-attached
portion and the bonding portion, a plurality of inner leads are
formed on the bonding portion; an image sensor chip having an
active surface and a back surface, wherein the active surface
includes a sensing area, a plurality bonding pads are formed on the
active surface around the sensing area, the back surface is
attached to the first die-attached portion, the bonding portion is
bonded on the active surface, the bonding pads are electrically
connected to the inner leads; a transparent cover disposed above
the sensing area; and at least an IC chip disposed on the second
die-attached portion.
2. The module of claim 1, wherein the IC chip is selected from the
group consisting of a controller chip, a DSP (digital signal
processor) chip, a memory chip, and an ASIC (Application Specific
Integrated Circuit) chip.
3. The module of claim 1, further comprising a plurality of passive
components mounted on the second die-attached portion.
4. The module of claim 1, wherein the bonding portion has an
opening aligned with the sensing area.
5. The module of claim 1, wherein the transparent cover is an
optical glass.
6. The module of claim 1, wherein the image sensor chip includes a
plurality of bumps formed on the bonding pads.
7. The module of claim 1, further comprising an annular sealant
disposed between the bonding portion and the image sensor chip to
hermetically sealing the sensing area.
8. The module of claim 1, wherein the bent portion has a bent
length greater than the thickness of the image sensor chip.
9. The module of claim 1, wherein the transparent cover is adhered
to the bonding portion.
10. The module of claim 1, wherein the inner leads are electrically
connected to the second die-attached portion through the bent
portion and the first die-attached portion.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an image sensor device, and
more particularly, to a multi-chip image sensor module having at
least an IC chip on a flexible module board.
BACKGROUND OF THE INVENTION
[0002] Image sensor devices have been widely implemented in
everyday lives, such as cellular phones, personal digital
assistants (PDA), digital still cameras (DSC), digital video
cameras (DV), video phones, video conferences, and so on. A
conventional image sensor package, as revealed in R.O.C. Taiwan
patent publication No. 542,493, entitled "Image sensor structure",
comprises a substrate, a protrusion layer, an image sensor chip,
and a light-transmission layer (glass cover). The image sensor chip
is disposed in the chip cavity formed by the substrate and the
protrusion layer. A plurality of signal input terminals are formed
on the upper surface of the protrusion layer to provide electrical
connections to the image sensor chip by a plurality of bonding
wires. Then, through the circuits on the sidewalls of the
protrusion layer and on the sidewalls of the substrate, the
electrical signals are transmitted to the substrate. An adhesive is
partially disposed on the upper surface of the protrusion layer to
adhere the light-transmission layer. However, the circuits on the
sidewalls of the protrusion layer is easily damaged due to lack of
protection. Furthermore, the image sensor package cannot be
miniaturized since the bonding wires occupy lots of space in the
chip cavity.
[0003] Another known image sensor device is revealed in R.O.C.
Taiwan patent publication No. 484,237, entitled "An optical device
with a tape packaging type". As shown in FIG. 1, an image sensor
package includes an image sensor chip 110, a flexible wiring tape
120, a molding base 130, and a transparent cover 140. The flexible
module board 120 is TCP type, which has an upper surface 121, a
bottom surface 122, and an opening 123. The inner leads of the
flexible module board 120 are thermally bonded to the bumps on the
image sensor chip 110 by ILB bonding. The molding base 130 has a
cavity 131 to accommodate the image sensor chip 110 where a sensing
area of the image sensor chip 110 is corresponding to the opening
123 of the flexible wiring tape 120 and outlet of the cavity 131.
In order to avoid the image sensor chip 110 from the damages of
moisture or dusts, the transparent cover 140 is adhered to the
sidewall 132 of the base 130. However, the molding base 130 is made
by molding, its thickness is much greater than the thickness of the
flexible wiring tape 120. Therefore, the total thickness of the
tape automated bonding package of optical devices cannot be
reduced. Moreover, no electronic component or passive components
are installed in the conventional packages.
SUMMARY OF THE INVENTION
[0004] The main purpose of the present invention is to provide a
multi-chip image sensor module including a flexible module board.
An image sensor chip and at least an IC chip are assembled on the
flexible module board. The flexible module board further has a bent
portion at the side of the image sensor chip and a bonding portion
above the image sensor chip to electrically connect the image
sensor chip by inner leads on the bonding portion. A transparent
cover is disposed above the image sensor chip. According, the
module thickness is thin and module function is easy to expand.
[0005] The second purpose of the present invention is to provide a
multi-chip image sensor module with a transparent cover. The
transparent cover is adhered to the bonding portion so that the
bonding portion is sandwiched between the transparent cover and the
image sensor chip. Accordingly, the bonding portion is fixed firmly
and a sensing area of the image sensor chip is hermetically sealed
by an annular sealant.
[0006] According to the present invention, a multi-chip image
sensor module mainly includes a flexible module board, an image
sensor chip, a transparent cover, and an IC chip. The flexible
module board has a first die-attached portion, a second
die-attached portion, at least one bent portion, and at least one
bonding portion, wherein the bent portion connects the first
die-attached portion and the bonding portion, a plurality of inner
leads are formed on the bonding portion. The image sensor chip is
attached to the first die-attached portion of the flexible module
board, and the IC chip is disposed on the second die-attached
portion. The image sensor chip has a sensing area with a plurality
of bonding pads formed around the sensing area. The bonding portion
is bonded on the image sensor chip by bending the bent portion such
that the inner leads are electrically connected to the bonding
pads. The transparent cover is disposed above the image sensor
chip. As a result, the analog and digital circuits of the
multi-chip image sensor module can be integrated by the flexible
module board.
DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a cross-sectional view of a conventional image
sensor package.
[0008] FIG. 2 is a three-dimensional view of a multi-chip image
sensor module according to the first embodiment of the present
invention.
[0009] FIG. 3 is a top view of a flexible module board of the
multi-chip image sensor module before assembly according to the
first embodiment of the present invention.
[0010] FIG. 4 is a cross-sectional view of the multi-chip image
sensor module according to the first embodiment of the present
invention.
[0011] FIG. 5 is a top view of a flexible module board for
assembling a multi-chip image sensor module according to the second
embodiment of the present invention.
[0012] FIG. 6 is a cross-sectional view of the multi-chip image
sensor module according to the second embodiment of the present
invention.
DETAIL DESCRIPTION OF THE INVENTION
[0013] Please refer to the attached drawings, the present invention
will be described by means of embodiment(s) below.
[0014] As shown in FIGS. 2, 3, and 4, a multi-chip image sensor
module 200 is disclosed according to the first embodiment of the
present invention, which includes a flexible module board 210, an
image sensor chip 220, a transparent cover 230, and a plurality of
IC chips 240.
[0015] Referring FIG. 3, the flexible module board 210 has a first
die-attached portion 211, a first bent portion 212, a second bent
portion 213, a third bent portion 214, and a second die-attached
portion 215. In this embodiment, the first die-attached portion 211
of the flexible module board 210 is rectangular for attaching the
image sensor chip 220 (as shown in FIG. 4). One of the sides of the
first die-attached portion 211 is integrally connected to the
second die-attached portion 215. The other sides are integrally
connected to the first bent portion 212, the second bent portion
213, the third bent portion 214 respectively. In addition, the
first bent portion 212 is flexible and connects a first bonding
portion 216, the second bent portion 213 connects a second bonding
portion 217, the third bent portion 214 connects a third bonding
portion 218. A plurality of inner leads 219 are formed on the first
bonding portion 216, on the second bonding portion 217, and on the
third bonding portion 218. The inner leads 219 are electrically
connected to an analog and digital circuit (not shown in the
figure) formed on the second die-attached portion 215 by traces
passing through the bent portions 212, 213, 214 and the first
die-attached portion 211.
[0016] Referring to FIG. 4, the image sensor chip 220 has an active
surface 224 and a back surface 225, wherein the active surface 224
includes a sensing area 221 for receiving images, a plurality of
bonding pads 222 are formed around the sensing area 221 on the
active surface 224. A plurality of bumps 223 may be formed on the
plurality of bonding pads 222 for bonding the inner lead 219. The
back surface 225 of the image sensor chip 220 is attached to the
first die-attached portion 211 of the flexible module board 210 by
an adhesive layer 251. By bending the first bent portion 212, the
second bent portion 213, and the third bent portion 214 toward the
peripheries of the image sensor chip 220, the first bonding portion
216, the second bonding portion 217, and the third bonding portion
218 are located above the active surface 224 of the image sensor
chip 220. By thermal compression, the inner leads 219 on the first
bonding portion 216, on the second bonding portion 217, and on the
third bonding portion 218 can electrically connect the
corresponding bumps 223 on the bonding pads 222 of the image sensor
chip 220. Usually each of the bent portions 216, 217, 218 has a
bent length greater than the thickness of the image sensor
chip.
[0017] Disposed above the sensing area 221 is the transparent cover
230 such as an optical glass. In this embodiment, the transparent
cover 230 is adhered to the first bonding portion 216, the second
bonding portion 217, and the third bonding portion 218 of the
flexible module board 210 by an adhesive tape 253. Accordingly, the
bonding portions 216, 217, and 218 are sandwiched between the image
sensor chip 220 and the transparent cover 230 to prevent from
displacement.
[0018] Preferably, an annular sealant 252 is disposed between
peripheries of the active surface 221 of the image sensor chip 220
and the first, second, third bonding portions 212, 213, 214 to
hermetically sealing the sensing area 221 and to encapsulate the
bumps 223 without covering the sensing area 221 of the image sensor
chip 220. The annular sealant 252 is a NCP (Non-Conductive Paste),
ACP (Anisotropic Conductive Paste), or a B-stage resin.
[0019] Referring to FIG. 2 again, the IC chips 240 are disposed on
the second die-attached portion 215 to electrically connect the
analog and digital circuit of the flexible module board 210. The IC
chips 240 are selected from the group consisting of a controller
chip, a DSP (digital signal processor) chip, a memory chip, and an
ASIC (Application Specific Integrated Circuit) chip. The controller
is used to control the image sensor chip 220 to receive images.
Through the DSP and the ASIC, analog image signals are converted
into digital image signals which are temporarily stored in the
memory chip. In this embodiment, the IC chips 240 include a chip
device 241 packaged in CSP (Chip Scale Package), a chip device 242
packaged in TSOP (Thin Small Outline Package), and a chip device
243 packaged in BGA (Ball Grid Array) type, a flip chip 244, and so
on. A plurality of passive components 245 also can be mounted on
the second die-attached portion 215. The passive components 245 are
used to eliminate the noise during transmission or to prevent
electrostatic shocks.
[0020] In order to synchronize the transmission of analog and
digital signals, the IC chips 240 disposed on the second
die-attached portion 215 of the flexible module board 210 are
electrically connected to the image sensor chip 200 by the inner
leads 219. Moreover, the first bent portion 212, the second bent
portion 213, and the third bent portion 214 of the flexible module
board 210 cover the sides of the image sensor chip 220 to save
consumption of encapsulating material and protect the image sensor
chip 220 from damages due to assembly or handling. Moreover, the
total module thickness of the module 200 is very thin.
[0021] FIG. 5 shows another flexible module board 310 for
assembling a multi-chip image sensor module 300 according to the
second embodiment of the present invention. FIG. 6 shows the
multi-chip image sensor module 300. As shown FIG. 6, the multi-chip
image sensor module 300 mainly includes the flexible module board
310, an image sensor chip 320, and at least an IC chip 340. As
shown FIG. 5, the flexible module board 310 has a first
die-attached portion 311, a bent portion 312, a bonding portion 313
and a second die-attached portion 314. The bent portion 312
connects the bonding portion 313 to one side of the first
die-attached portion 311. The second die-attached portion 314
extends from one of the other sides of the first die-attached
portion 311. A plurality of inner leads 315 are formed on the
bonding portion 313. In this embodiment, the bonding portion 313
has an opening 316. When the bonding portion 313 is bonded on the
image sensor chip 320, the opening 316 is aligned with a sensing
area 321 of the image sensor chip 320.
[0022] Referring to FIG. 6 again, the image sensor chip 320 is
attached to the first die-attached portion 311, the IC chip 240 is
disposed on the second die-attached portion 314. A transparent
cover 330 is disposed above the sensing area 321 by adhering to
peripheries of the active surface of the image sensor chip 320. The
image sensor chip 320 includes a plurality of bumps 323 on its
bonding pads 322. The inner leads 315 are electrically connected to
the bumps 323, so that the image signals from the image sensor chip
320 can be transmitted to an analog and digital circuit formed on
the second die-attached portion 314 through the bonding portion 313
and the first die-attached portion 311. Furthermore, image signal
can be transmitted to the IC chip 340. Preferably, an adhesive 350
is disposed between the image sensor chip 320 and the bonding
portion 313 to prevent the displacement of the bonding portion 313.
The IC chip 340 disposed on the second die-attached portion 314 can
integrate the analog and digital signals in the image sensor module
300.
[0023] The above description of embodiments of this invention is
intended to be illustrative and not limiting. Other embodiments of
this invention will be obvious to those skilled in the art in view
of the above disclosure.
* * * * *